code: def encode(input, output):
      """Encode a file; input and output are binary files."""
      while s := input.read(MAXBINSIZE):
          while len(s) < MAXBINSIZE and (
              ns := input.read(MAXBINSIZE - len(s))
          ):
              s += ns
          line = binascii.b2a_base64(s)
          output.write(line)
  
imports: import re
  import struct
  import binascii
label_desc: Use image node_id 21 for calling a global function with example usage: encode(input, output) without return types